This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The spindle is a complex mechanical apparatus that segregates chromosomes during cell division in eukaryotes. A network of complexes comprises and regulates this dynamic structure to ensure fidelity of chromosome inheritance. In Saccharomyces cerevisiae, over one hundred proteins have been identified with a role in spindle function. To further complete our understanding of this mechanism and to identify novel components, we have collaborated with the Yeast Resource Center to construct an extensive physical-interaction map of the budding yeast spindle.